Abstract: This study was aimed to detect the single nucleotide polymorphism (SNPs) of Holstein cows diacylglycerol acyltransferase 1 (DGAT1) gene in exon 8, and to predict the protein structure and function caused by the mutations and discuss the evolution relationship of DGAT1. PCR-SSCP combined with sequencing was used to detect the SNPs in exon 8 of DGAT1 gene. Bioinformatics approach was used to predict the physicochemical properties and structures of DGAT1 protein. The approach was also used to analyze the amino acid homology of DGAT1 between different species, and to build the evolutionary tree. The PCR-SSCP analysis results showed that a double mutations existed in exon 8 of DGAT1 gene, namely M694 and M695.The prediction of protein structure and function displayed that the double mutation had no influence on the physicochemical properties and structures of the protein, but led to the changes in the component of its protein function domain. The evolution analysis results indicated that amino acid sequence homology of DGAT1 between Holstein cows and sheep was the highest (99.1%), and the homology between Holstein cows and chimpanzees was the lowest (65.3%).

Key words: Holstein cows; diacylglycerol acyltransferase 1 gene; single nucleotide polymorphism (SNPs); bioinformatics